1. Field of the Invention
This invention relates to the control of flow through a conduit by the use of a butterfly type valve having extendible sectors that further increase the restriction of fluid flow through a conduit.
More particularly, this invention relates to a finite control of fluid flow through a body, such as a rocket motor case, wherein the butterfly type, flow constriction valve, having extendible sections therein, is positioned with its rotation axis in the plane of the throat of the nozzle of the thrust engine. Thrust vector control is possible in a plane that is perpendicular to the axis or hinge pin of the butterfly valve or disc.
2. Prior Art
There are many butterfly type valve devices in the prior art. One in particular, U.S. Pat. No. 1,706,020, describes a butterfly valve device positioned within a constricted area of a conduit. The butterfly valve allows maximum flow when the plane of the flow restrictor disc is parallel with the axis of a conduit, the butterfly providing a further restriction or stoppage of the flow by turning the plane of the disc in a direction which would be perpendicular to the axis of the conduit. However, if the butterfly disc device is smaller than the opening in the conduit so that when the butterfly is perpendicular to the axis of the conduit, flow is still able to pass around the peripheral edge of the disc, there is no additional flow control to monitor the amount of flow passing around the fixed, open disc. The present invention contemplates a butterfly type valve which has an outside peripheral dimension smaller than the inside diameter of the conduit in which the valve is positioned. When the valve is positioned in a plane perpendicular to the axis of the conduit, flow is able to pass around the peripheral edge of the valve. The present invention provides a finite control of the fluid passing around the disc by providing extendible segments in the disc, thus distinguishing over the prior art valve just described.
Another U.S. Pat. No. 2,724,405, discloses a pintle type of fixed obstruction positioned within a conduit. Around the peripheral edge of the pintle is an extendible, resilient section that can be expanded out into the area surrounding the outside peripheral edge of the pintle. The device can either shut off the flow entirely, or vary the flow past the lip of the resilient seal. The present invention has a much wider range of flow control since it is a non-fixed type of restriction, as opposed to a fixed pintle in a conduit. Additionally, the present invention has a capability of vectoring fluid flow out of a conduit which has obvious advantages in a rocket engine.
Yet another prior art U.S. Pat. No. 3,556,489, describes a pintle device positioned within a constricted throat of a conduit, the center portion of the pintle adjacent the narrowest throat region of the conduit being expandable so as to control the flow through the throat. This device, like the foregoing patent, controls flow uniformly through the constriction, thus providing a narrow range of flow control through the constriction. Again, the present invention has a much wider range of flow control in that the non-fixed butterfly valve may be positioned from a maximum flow to a minimum flow with additional precise control over the fluid passing by the extendible sectors in the disc.